Truing apparatus



y 1955 E. F. s-r. ANDRE 2,708,433

TRUING RPPABATUS Filed Jan. 29, 1954 h2g2 {E7 l6 INVENTOR. 3 Z? EDWARD F SIANDRE 5'0 /7 ,5 BY M g /0 M U). 921

ATTORNEY United States Patent TRUING APPARATUS Edward F. St. Andr, Worcester, Mass., assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Application January 29, 1954, Serial No. 406,991 3 Claims. (Cl. 125-11) The invention relates to grinding machines, and more particularly to a grinding wheel truing apparatus for tru ing a predetermined shape on the operative face of a grinding wheel.

One object of the invention is to provide a simple and thoroughly practical grinding wheel truing apparatus. Another object of the invention is to provide a radialtype truing apparatus for truing both a straight cylindrical face on a grinding wheel and a radius on one or both corners of the grinding wheel. Another object is to provide a radial-type truing apparatus which is particularly adapted for truing the operative face on a wide-faced grinding wheel. Another object is to provide a radialtype truing apparatus with a circular track having end sections which may be moved to inoperative positions for truing the wide straight face on the grinding wheel. Other objects will be in part obvious or in part pointed out hereinafter.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. 1 is a fragmentary cross-sectional view of a grinding machine, showing the grinding wheel truing apparatus;

Fig. 2 is a plan view, on an enlarged scale, of the radial truing apparatus; and

Fig. 3 is an end elevation, on an enlarged scale partly broken away and shown in section to clarify the illustration.

A grinding machine has been illustrated in the drawing comprising a base having a transversely movable wheel slide 11 mounted on ways (not shown) on the base 10. The wheel slide 11 supports a rotatable wheel spindle 12 which in turn supports a rotatable grinding wheel 13.

The grinding wheel slide may be moved transversely by any of the well known feeding mechanisms, such as, that shown in the prior U. S. patent to C. H. Norton No. 762,838, dated June 14,1904, to which reference may be had for details of disclosure not contained herein. The wheel feeding mechanism may comprise a half-nut 14 depending from the underside of the wheel slide 11 which engages or meshes with a rotatable feed screw 15 journalled in suitable bearings (not shown). The left hand end of the feed screw 15 is provided with a gear 16 meshing with a gear 17 mounted on the right hand end of a rotatable shaft 18. The shaft 18 is rotatably supported in bearings (not shown) in the base 10 and is provided with a gear 19 on its left hand end which projects from the front of the machine base 10 which may be turned by a manually operable feed mechanism, such as that shown in the prior patent to Norton above referred to.

A longitudinally movable table 25 is slidably mounted on a flat way 26 and a V-way 27 and is arranged so that it may be moved longitudinally relative to the base 10. The table 25 supports a swivel table 28 which, as shown in the above-mentioned prior patent, serves as a support for a headstock and a footstock (not shown) or a truing apparatus, as illustrated in the drawing.

The table may be moved longitudinally either manually or by means of a power operated traversing mechanism. For the sake of simplicity of illustration, however, a manually operable hand traverse mechanism has been illustrated. The table 25 is provided with a depending rack bar 29 which meshes with a gear 30 mounted on the right hand end of a rotatable shaft 31. The outer end of the shaft 31 is provided with a manually operable traverse wheel 32 so that the table may be traversed longitudinally in either direction relative to the base 10 by rotating the hand wheel 32.

The improved truing apparatus has been illustrated as mounted on the swivel table 28 of a grinding machine, as described above. The truing apparatus comprises a base member 35 which is provided with bearing surfaces 36 and 37 arranged to mate with correspondingly shaped surfaces on the swivel table 28. The truing apparatus base 35 is arranged so that it may be clamped rigidly to the swivel table 28 by means of a clamping member 38 which is pivotally supported by a stud 39 and is arranged to engage a dove-tailed surface 40 formed on the upper surface of the swivel table 28. The clamping member 38 is actuated by means of a clamping screw 41 so that the truing apparatus base 35 may be rigidly clamped in the position on the swivel table 28.

The truing apparatus comprises a pivotally mounted frame 42 which is arranged to swing about a fixed axis in a circular path. The lower end of the frame 42 is supported by a vertically arranged shaft 43 which is mounted in spaced anti-friction bearings 44 and 45 mounted in fixed relationship with the truing apparatus base 35. The upper portion of the truing apparatus base 35 is provided with a circular track 46. The track is fastened to the base 35 by means of screws 47. The upper portion of the frame 42 is provided with a follower plate 48 which is provided with a circular face arranged to mate with the circular face of the track 46. The upper end of the frame 42 is provided with a housing 50 which is arranged to support a transversely adjustable truing tool support 51 having a diamond nib 52 mounted on its right hand end. The truing tool holder 51 is arranged to be clamped in adjusted position relative to the frame 42 by means of a clamping screw 53.

In order to true a radius of a predetermined extent, the truing tool holder 51 is adjusted transversely relative to the axis of the shaft 43 so that when the frame 42 is swung in a circular path as guided by the track 46, the diamond or truing tool 52 will generate a predetermined radius on the grinding wheel 13.

In order to true a straight cylindrical face on the periphery of the grinding wheel 13, a suitable means is provided for holding the frame 42 in a fixed position so that the truing tool may be traversed in a straight line by traversing of the work table 25 lingitudinally. As illustrated in the drawing, the base member 35 is provided with a rock shaft 55 supported in an upwardly extending boss 56 formed integral with the base member 35. A pair of rock arms 57 and 58 are keyed to opposite ends of the rock shaft 55. The arms 57 and 58 are provided with adjustable stop screws 58 and 59 respectively. When the arms 57 and 58 are swung into the positions illustrated in Figs. 2 and 3, the stop screws 58 and 59 will engage the side faces of the housing 50 so as to hold the base member 42 in a fixed position. With the parts in the position just described, the table 25 may be traversed longitudinally to move the truing tool or diamond 52 in a straight line path to true a cylindrical surface 60 on the grinding wheel 13.

in order to true a straight cylindrical face and two adjacent radii on a wide-faced grinding wheel, it is necessary to have a relatively long traversing movement of the table 25 so that the truing tool 52 may true the entire cylindrical face thereof. The circular track 46 is provided with a pair of end sections 61 and 62 which are pivotally supported on a pair of axially aligned studs 63 and '64 which-are supported by a pair of bosses 65 and 66 respectively formed integral with the truing apparatus base 35. A pair of clamping nuts 67 and 68 are provided to clamp the segments 61 and 62 either in an operative position as shown in full lines in Figs. 2 and 3 or in an inoperative position as shown in broken line 61a in Fig. 3. Each of the segments 61 and 62 are provided with integral rearwardly extending arms 76 and 71 re spectivcly each of which is provided with adjustable stop screws 72 and 73 which engage a stop surface 74 formed on the base member 35.

The segments 61 and 62 are provided with stop screws 75 and 76 respectively to limit the swinging motion of the truing apparatus frame 42 when truing a radius.

In order to true the straight cylindrical face 6% and a radius 77 and 78 at either end thereof on the grinding wheel 13, it is first desirable to true the cylindrical face. In the case of a wide faced wheel such as illustrated in the drawings, the clamping nuts 67 and 63 are loosened and the track segments 61 and 62 swung into a vertical position after which the clamping nuts 67 and 68 are clamped to lock them in an inoperative position. The grinding wheel face may then be trued by a traversing movement of the table 25 and the grinding wheel may be advanced to produce the desired truing by actuation of the feed mechanism as above described.

After the cylindrical face 60 has been trued, the track segment 62 may be swung downwardly into an operative position after which the table 25 may be traversed longitudinally to position the axis of the pivot stud 43 of the frame 42 in alignment with the axis of the radius 78 to be generated. The arms 57 and 58 may be then swung in a counterclockwise direction (Fig. 3). Then the frame 42 may be swung in a circular path with the follower plate 48 engaging the operative face of the track 46 to generate the radius 78. After the radius 78 has been generated, the track segment 62 may be swung t to an inoperative position. The table 25 may then be traversed so that the axis of the truing apparatus frame supporting stud 43 is aligned with the axis of the radius 77 on the grinding wheel 13. With the parts in this position, the track segment 61 may be swung downwardly K into an operative position as illustrated in Fig. 2 after which the truing apparatus frame may be swung in a circular path so that the truing tool 52 generates or trues the radius 77 on the other corner of the grinding wheel. It will be readily apparent from the foregoing disclosure that the truing apparatus may be utilized to true a cylindrical face on a wide faced wheel together with a radius on one or both corners of the grinding wheel 137.

The operation of the improved truing apparatus will be readily apparent from the foregoing disclosure. The truing tool holder 51 is first adjusted relative to the housing 50 so that the diamond or truing tool 52 is positioned at a predetermined distance from the axis of the frame 42 which is equal to the radius to be generated on the corners of the grinding wheel to be trued. The truing operation on the grinding wheel 13 then proceeds in a manner above described.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forthtogether with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to-be understood that all matter hereinabove set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a truing apparatus for grinding machines having a truing apparatus base, a pivotally mounted frame thereon which is arranged to swing in a circular path, a truing tool adjustably mounted on said frame, a circular track on said base to guide said frame, an end section pivotally supported on one end of said track, said section being normally aligned with'said track, and clamping means tohold said section in either an operative or an inoperative position to facilitate truing a cylindrical face an adjacent radius on the periphery of a grinding wheel.

2. In a truing apparatus for grinding machines having a truing apparatus base, apivotally mounted frame thereon which is arranged to swing in a circular path, a truing tool adjustably mounted on said frame, a circular track on said base, a follower on said frame which engages said track to guide said frame in truing a radius on a grinding wheel, an end section pivotally mounted on each end of said track which is normally aligned with said track, and independent clamping means to hold said sections in either an operative or inoperative positions to facilitate truing a'cylindrical face an adjacent radius at one or both ends thereof.

3. In a grinding machine as claimed in claim 2, in combinationwith theparts and features therein speci-' tied of an adjustable stop screw on each of said pivoted sections to facilitate aligning the section with said track when in an operative position, and means to clamp said end sections in either an operative or inoperative position.

References Cited in the file of this patent UNITED STATES PATENTS 

